This will be the first child for Simpson, who has previously expressed her desire to have fiancé Eric Johnson's babies.

"I definitely see myself having a family with him, so that's exciting to think about," Simpson said shortly after her beau, a former NFL athlete, popped the question last November.

The baby on the way will be the second grandchild for Simpson's parents Joe and Tina, who first became grandparents in Nov. 2008 when daughter Ashlee Simpson and her ex-hubby Pete Wentz gave birth to son Bronx.